


mikan

by punicagranatum



Category: Haikyuu!!
Genre: Anal Sex, Come Eating, Established Relationship, Help! My Boyfriend Became a Highschooler Again and I May Have Had ThoughtsTM About Him Back Then, M/M, MSBY Black Jackals Sakusa Kiyoomi, Physically Karasuno Hinata Shouyou, the only thing that needs help is hinata's poor ass
Language: English
Status: Completed
Published: 2020-08-20
Updated: 2020-08-20
Packaged: 2021-03-06 19:14:20
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,253
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26003992
Author URL: https://archiveofourown.org/users/punicagranatum/pseuds/punicagranatum
Summary: “How did this even happen?”Kiyoomi could hear Miya losing his mind, but he gave up trying to understand why Shouyou looked a good ten centimeters shorter and at least ten kilos lighter. He gave up on logic after the first six months he spent as an MSBY Black Jackals player, especially after Bokuto started a fire after pressing on a faulty fire alarm. So if Shouyou was now a highschooler again, it was just that the gods were getting creative with the ways they had to punish him for some past life karma.
Relationships: Hinata Shouyou/Sakusa Kiyoomi
Comments: 16
Kudos: 336





	mikan

**Author's Note:**

> you're gonna tell me Kiyoomi took one (1) look at Hinata and remembered him for six entire years out of his undying love for volleyball? ok, alright. i disagree, here's an essay on why

“How did this even happen?”

Kiyoomi could hear Miya losing his mind, but he gave up trying to understand why Shouyou looked a good ten centimeters shorter and at least ten kilos lighter. He gave up on logic after the first six months he spent as an MSBY Black Jackals player, especially after Bokuto started a fire after pressing on a faulty fire alarm. So if Shouyou was now a highschooler again, it was just that the gods were getting creative with the ways they had to punish him for some past life karma.

“Omi-san,” Shouyou looked almost bashful. 

“You remember us?”

“Yeah…I don’t know what happened but I’m the same except physically.”

“That’s good,”Kiyoomi nodded, turning to leave. After a few steps, he turned again to the group, looking straight at Shouyou. “So? You’re not coming home?”

The other players looked at him like he had grown a second head, but Shouyou joined him and waved at the rest, uncharacteristically shy.

The ride home was also uncharacteristically silent, where Shouyou would normally talk Kiyoomi’s ears off with whatever nonsense Miya or Bokuto was up to. Once they were inside their apartment, Kiyoomi paused while he was stowing away his belongings.

“How do you feel?”

Shouyou took a second to answer, assessing while Kiyoomi walked up to him. “Good. I guess? I feel okay, just different.”

“Good.”

“Good?”

“Yeah. Good.”

Picking Shouyou up was like picking a baguette or something similarly light. He weighed nothing as Kiyoomi pushed him against the wall. Kiyoomi breathed him in, wondering if Shouyou smelled the same during high school. Probably not.

“O—omi-san?”

“Hmm. If I told you that I first started thinking about you when you were Mr. Got-a-Fever, bouncing on the court like a human-shaped mikan, what would you say?” Kiyoomi hummed while he took Shouyou’s red-tinted earlobe between his teeth.

“I—Really?” That sounded vaguely insulting, vaguely flattering.

“Yeah…” Kiyoomi put his hands around Shouyou’s small waist, amazed at the feeling of his own fingers touching, encircling him completely. His mouth felt terribly dry.

“I want to split you in half over my cock. Are you amenable?”

Shouyou choked on air.

“I don’t have all day.”

“Ah—yes, yes, please,” he sputtered.

Shouyou couldn’t even inhale air back into his lungs that Kiyoomi had already put him back on the floor. He knelt between his legs, running his hands all over his torso, leaving Shouyou to wonder if they felt bigger than usual because he was smaller or if it was just his horny brain at work. He had a growing obsession over them: they were big, pretty with his long fingers and maintained nails, and harsh on his skin from the calluses that came from years of volleyball. The first time Shoyou had seen Kiyoomi singlehandedly grab a ball, he wished that he had his head as roughly grabbed as the ball. Seeing them now, enormous against his slimmer thigh, was intoxicating. Shouyou dizzily watched as one spread from the top of his thighs to just over his belly button.

Kiyoomi quickly undid the knot of his sweatpants, dragging them down his legs. He wasted no time taking his half-hard dick into his mouth, lapping all over him with his pristine tongue. The thrill of dirtying him never got old for Shouyou, especially when Kiyoomi made a show of the way spit mixed with precum, glossing his pretty lips. Suddenly, those lips moved and Shouyou took five whole seconds to understand what they said:

“You have twenty seconds to grab the lube if you want me to finger you or you’re doing it.” 

Shouyou scrambled to find the lube that he kept in his bag for this exact reason, almost falling face first because his pants were still around his ankles. He still got it before time ran out. He gave the lube to Kiyoomi, who put it in his pocket and picked him up again like he was a bag of rice. He walked to their living room and sat on their couch, letting Shouyou drop into his lap. Shouyou took his time, leaving sweet kisses and faint nips all over his neck, running his small hands into curly hair. Yet, after a couple of seconds he realized that Kiyoomi’s hands hadn’t moved from his hips. He hoped a small whine and a rough grind of his hips would convey what he wanted, but Kiyoomi didn’t move. Rather, his grip on his hips turned harsher, fingers digging into his flesh and nails stabbing his sensitive skin.

“If you’re so needy then you should do it yourself,” Kiyoomi whispered into his ear.

“But you promised that you’d do it,” Shouyou protested. “Come on, I really want you to do it.”

Kiyoomi settled even more deeply into the couch. “That’s sad,” he hummed, not sounding sad at all. “I changed my mind. Do it right here, over me.”

Shouyou looked like he wanted to argue even more, but something in the way Kiyoomi was staring like he could read his mind made him bite his complaints back.

“Fine,” he said through gritted teeth, even though he didn’t really mind. At least, it gave him a front-row seat to Kiyoomi’s twisting face while he worked one, then two, then three fingers inside him. 

Shouyou took his time, enjoying the way he felt Kiyoomi grow bigger and harder against his thighs while he moved uselessly underneath him, like he couldn’t help it. One of his hands was still gripping his hip, but the other one now clung to the top of his thigh, where one finger was barely touching the meat of his ass, like he was trying to wait and running out of patience.

Kiyoomi also had a wonderful view. Shouyou couldn’t even tower over him and he was struggling to keep upright on his lap, his thighs spread wide over Kiyoomi’s hips while a small hand dug sharply into Kiyoomi’s shirt and shoulder. His cock sprang against his stomach with the movements of his arm that Kiyoomi couldn’t see but could definitely imagine. But the best part was his face. Shouyou’s cheeks were flushed, a rosy red running high on his cheek, his slack lips let sighs and small grunts pass through and sweat glowed like dew on the skin of his throat. Kiyoomi had had enough. He brought his lips to damp skin. His waiting had to pay now.

“Please tell me you’re ready before I snap and decide to just fuck your mouth.”

“Ha… Suit yourself, Omi-san,” Shouyou said between pants and a short laugh. “It’s your pervy high school fantasy anyways.”

Kiyoomi decided that that answer deserved some punishment, so he bit on the skin of his throat maybe a little harsher than intended, forcing a yelp out of Shouyou.“Glad we’re on the same page.”

He sighed with delight when he finally palmed himself, achingly hard from allowing Shouyou to tease him and not touching himself since they got home. He pulled down his trousers fast and efficiently even with Shouyou on top of him, surprising both of them. He also decided to pull both their shirts off, savoring the feeling of skin against his hand. Finally, he spread Shouyou’s cheeks apart and let the tip of his cock rub against his hole.

Slowly—so, _so_ cautiously—, he started lowering Shouyou onto his cock. It was tight, so damn tight, _impossibly tight_. Almost immediately, Shouyou went rod-rigid against him.

“Shit…,” He choked.

Kiyoomi soothed him with numbing circles of his fingers on his back. He couldn’t help but appreciate the beauty of the tears that clung to Shouyou’s lashes, of the blush that stained him from his cheeks to his chest, of the trembling that shook his entire body. A walking wet dream, a pervy fantasy indeed. Delighted, he watched Shouyou struggle to fit centimeter after centimeter inside him until he jerked upright and shot him the dirtiest look he could.

“You wanted me to finger myself because my fingers are thinner now, you absolute jerk,” he growled while Kiyoomi snickered.

“Giving up?” he mocked, knowing what answer he would get.

“As if, jackass! I’m gonna make you cum so hard you pass out and when I get back to normal I’ll make you choke on my dick!” 

_Choke on my dick_ and high school Shouyou made for a funny comparison. But he shut his mouth and watched with awe and respect as Shouyou worked every part of him inside, surrounding him like a white-hot vice.

Shouyou’s thighs shook with effort as he rode him, forcing grunts out of both of them. Kiyoomi thought that maybe he had underestimated him, as he felt Shouyou pull the orgasm out of him, his insides burning him in velvety hell. Still, even if this Shouyou had the motivation and the fighting spirit, he currently didn’t have the core and leg strength that he got from the years upon years of playing volleyball for a living. Kiyoomi watched him struggle to keep up, frustrated groans leaving him, and charitably decided to help him again.

His hands found Shouyou’s teeny-tiny waist again and Kiyoomi started fucking into him, forcing him to meet his hips. Shouyou’s moans surrounded them in the silence of their apartment, punched out of his small body by the force of Kiyoomi’s pace. 

“Fuck…” he said mindlessly. “So fucking big…”

One of his hands slid over Kiyoomi’s, touching his stomach where Kiyoomi’s cock was hitting inside of him. Kiyoomi took a quick look at this and had to convey all his efforts into not coming immediately. Daring to take a look at Shouyou’s face wasn’t a good alternative either, spit was escaping from the corner of his mouth and tears finally spilled from his copper lashes. Was Kiyoomi going to hell for thinking it was the hottest thing he ever saw? Maybe, he decided.

“I’m gonna break you,” Kiyoomi grumbled, fucking him even harder, “God, I’m gonna make you fall apart and then come all over your pretty little face.”

Shouyou’s hands dug into his shoulders, fisting his hair desperately as he pleaded.

“Omi-san,” he panted. “Omi-san, Omi-san–Can I touch myself?”

“Hmm,” Kiyoomi faked to ponder. Shouyou threw himself on him, kissing him all over his face, taking an ear into his mouth and nibbling fervently.

“Please, please, please,” he begged. “I’m gonna be so good, please—Omi-san, I’ll do my best for you, please.”

Kiyoomi didn’t answer. Instead, he took Shouyou’s leaking cock into his and started jerking him almost at the same maddening pace that he was fucking him.

“Ah! Fuck!” Shouyou shouted, trying hard not to collapse on Kiyoomi’s lap. “Yes, yes, yes. Omi-san, fuck.”

In a surprising display of strength of his slim legs, Shouyou fucked himself hard on his cock, alternating between impaling himself deep and harsh and thrusting desperately in the tight fit of Kiyoomi’s fist over him. His voice was raw, moaning wantonly. Shouyou clenched almost painfully tight around him, continuing the chants of _yes_ and _Omi-san_ and _please_ , until his back curbed impossibly and he came all over Kiyoomi’s stomach.

Once he came to his senses, Shouyou frowned slightly and, looking pitiful, approached to lick the stripe of cum hanging perilously onto Kiyoomi’s jaw. He pecked some more kisses over his face, but Kiyoomi pushed him back and off him, letting his knees hit the cold floor. Kiyoomi thought he looked beautiful, as he replaced him with his hand. But he knew this was going to be over soon and he really, really, wanted to come all over Shouyou’s freckled face.

Shouyou was watching him, head on his thigh, running a hand on the other one. His big brown eyes were clouded in post-orgasmic bliss as he followed the movement of his own fingers on his aching cock, just on the verge of release. He urged Kiyoomi closer to the edge of the couch and his tongue ran over his own fingers as he started licking hungrily at his balls. When he felt them tighten against him, he put his hands over Kiyoomi’s, guiding him to his open mouth and letting him drip all over his face like honey over cut peaches.

“Good boy,” Kiyoomi hummed appreciatively as he watched cum pooling in Shouyou’s tongue. 

He had never seen a prettier picture. Shouyou looked debauched, defiled and downright succulent. Kiyoomi took his lovely face between his hands and licked every drop off him. Feeling especially nice, he kissed him deeply and the salty tang of cum was shared between them as he gathered Shouyou into his lap again.

Both of them stayed in silence for a while, cuddling as their breaths normalized again and they let the endorphins do their work.

“Should we be concerned about this?” Shouyou asked, not really sounding all that anxious despite the surrealness of becoming a 15 years old again, at least physically.

“If you don’t change in the next few days, I’ll take you to the doctor,” Kiyoomi simply answered.

“Good.”

“Good.”

“I didn’t know you had a thing for me during high school,” Shouyou teased.

“You think I just remember anyone I crossed paths with in my long volleyball career?” Kiyoomi teased back. “You really think highly of yourself, huh?”

“I—You know what I mean!”

“Yeah, yeah, whatever. Let’s go shower.” Not waiting for an answer, Kiyoomi simply picked up an outraged Shouyou again and went to the bathroom, hoping he could have a little more fun while it—whatever it was—lasted.

**Author's Note:**

> thank you for reading this! i hope you enjoyed it! comments are always appreciated :)
> 
> my [ twt ](https://twitter.com/_punicagranatum)


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